Subtle highlighting in IOS 6.1.  This article: http://goo.gl/JmVRJ pointed it out in the lock screen.  I found it in the Music app as well.  To see the subtlety of the highlighting, flip back and forth between these two screen shots.  The first was taken while leaning the phone to the left, the second while leaning the phone to the right.
[edit] D'oh!  This was in 6.0, too.
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January 29, 2013 (2 photos)
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